Each day, we make the same choice hundreds of times: whether to lie or tell the truth. It often happens without thinking, and we ignore the profound impact of these seemingly inconsequential decisions. Even the smallest lies can cost you money, impact your relationships, and affect your choices. Conversely, honesty offers many surprising psychological benefits. Here's how truth and lies affect your brain and your life every day.

Little Lies Can Cost You Money

You're out at a restaurant and your server comes by to ask you how you like your food. You say everything's great. The food is okay, but you don't want to be rude so you lie. It may not seem like a big deal, but when the check comes you'll be overly generous with your tip. This is one example of how white lies actually affect your behavior. Psychologist Guy Winch, writing for Psychology Today, explains:

[Researches Argo and Shiv] found that 85% of diners in restaurants admitted to telling white lies when their dining experiences were unsatisfactory (i.e., claiming all was well when it wasn't). However the real interesting finding was that diners who told white lies to cover up their dissatisfactions were then likely to leave bigger tips than those who did not. Why would diners who were less satisfied with their meals and who lied to their server about it leave an even bigger tip as a result? The researchers propose that cognitive dissonance was at play.

Conigitive dissonance describes the discomfort you feel when holding two (or more) conflicting thoughts, and it shows up a lot when you lie. In another study by Argo and Shiv, University students received a short list of words with which to form sentences. Some participants received lists containing basic words that had no real meaning behind them, but others received lists of words related to honesty. Then, the research assistant purposefully left the participants in the room with nothing to do for about 12 minutes just to annoy them. Upon returning, she asked some students how they felt. Most said "fine," which was obviously a lie because they were clearly annoyed.

After this initial test, the researchers invited the participants to a second study with a raffle prize of $100. They also asked the participants if they'd like to donate a portion of their winnings back to the study. Anyone primed to think about honesty and told a white lie in the first experiment offered up more than half their money (on average). Everyone else opted to donate about one third of their potential raffle winnings. Again, cognitive dissonance reared its head when the conflict of lying came to mind.

We ignore white lies because they seem harmless. They rarely resurface in conversation, but while their future effects are subtle they do exist in profound ways. As a result, it's necessary to look at the long term effects of our actions even when the consequences seem benign or even non-existent.

Lies Tax Your Brain, Cause Stress, and Harm Your Body

Lying requires a lot of effort. When you tell the truth, you simply remember what happens. When you lie you have to consider what you're trying to hide, figure out a believable version of the opposite, give a convincing performance to sell that lie, and then remember it for the rest of eternity so you never get caught. Even if you're pretending to love your grandmother's disgusting fruitcake, that's a lot of pressure. Furthermore, it builds and builds every time you lie. (And you all do, even if you don't think so.) According to deception expert Pamela Meyer, the average person lies three times within the first minute of meeting a stranger and between 10 and 200 times per day. We handle this constant lying well considering how remarkably often it occurs, but that's especially easy to do when we have an easy time ignoring the consequences.

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Anita Kelly and LiJuan Wang of Notre Dame recruited a group of 110 people from 18 to 71 years old, and told them that once a week for ten weeks they'd have to come in and, in a lie detector machine, report how many times in the previous week they had lied. But the group was divided in half. 55 of them got explicit instructions in how to avoid lying. (They could avoid telling the truth, or not answer, just not out and out confabulate.) The other group got no instructions, just the request to come in once a week and tell the truth about how many times they had lied last week.

Everybody lied less. But the group that had gotten advice on how to avoid lying reduced their fabrications far more. And in questionnaires, those who had lied less reported better mental and physical health. They reported improvements in their relationships, less trouble sleeping, less tension, fewer headaches, and fewer sore throats.

You probably know thatstress harms your brain and body in several horrible ways. Since lying contributes to your stress level and you do it many, many times per day, you need to consider the impact of your secrets. The harm isn't self-evident, but it readily exists in the numerous health issues you encounter in your daily life.

Sometimes Honesty Is Not Always the Best Policy

Life has no paradigms. Lying cause stress and other awful problems, but it's useful and even necessary at certain times. When lying assures your safety or honesty puts you in danger, you probably shouldn't choose the truth. Exceptions always exist, and regardless of our intentions we're not going become model truthtellers no matter how comfortable we feel. Generally speaking, honesty provides far more mental and physical health benefits than dishonesty. Nevertheless, we're complicated creatures. We make complicated decisions every day. We'll find reasons to lie that are necessary, but we'll naturally find more that aren't. Watch out for instances when you lie out of politeness and to preserve your own self-esteem. Think about the long-term effects and not how the lie will protect you, or someone else, in a particular moment. You can't always tell the truth, but the more you do the happier your brain and body will be.